Causes

The exact cause of sarcoidosis is unknown. Granulomas appear to be the result of an immune system response to an unidentified trigger. Infections agents as well as environmental exposures are thought to be possible precipitants for this immune response; however, no clear triggers or causes have been identified. Genetic mutations in white blood cell proteins (called human leukocyte antigens, or HLA) as well as chemicals that control inflammation (called cytokines) have also been linked to sarcoidosis.